Apparatus for forcing off mouth skulls



Oct; 31, 1967 o. PUHRINGER 3,350,081

APPARATUS FOR FORCING OFF MOUTH SKULLS Filed Oct. 27, 1964 sSheets-Sheet 1 I N VENTOR.

OTH/MR PUHRWGER his ATTORNEYS Oct. 31, 1967 o. PUHRINGER APPARATUS FORFORCING OFF MOUTH SKULLS 3 Sheets-Sheet 2 Filed Oct. 27, 1964 INVENTOR.OTHVIA R PUHRINGER le-MM his ATTORNEYS Oct. 31, 1967 o. PUHRINGER3,350,081

I APPARATUS FOR FORCING OFF MOUTH SKULLS Filed Oct. 27, 1964 aSheets-Sheet s I N VEN TOR.

0TH MAR PUHRINGER W-EMMWM his ATTORNEYS United States Patent toVereinigte ABSTRACT OF THE DISCLOSURE This invention relates toapparatus for removing skulls from the mouths of crucibles or convertersand includes a pivoted member having an inclined nose portion which isforced against the skull during tilting of the converter or crucible bya hydraulic pressure system including a pressure-regulating device forlimiting the maximum force with which the skull-removing nose is pressedagainst the skull to avoid damaging the converter during removal of theskull.

This invention relates to an apparatus for forcing olf skulls from themouths of tiltable crucibles or converters.

During the operation of refining vessels, a mixture of slopped slag andsteel particles in the form of a sintered mass, described as a skull,accumulates at the mouth of the vessel and must be removed from time totime. This removal involves undesired standstill times.

Various methods may be adopted to remove a skull: The skull may be burntoff with oxygen flames or may be blown off with impact and thrustingdevices when the crucible is in a tilted position. In many cases, themouth of the crucible and the skull adhering thereto were moved by meansof the tilting drive against a rigid obstacle and the skull was forced01f by the force of the crucible drive. This method, however, gives riseto unforeseeable forces, which react on the drive and may easily damageor even destroy the same. For this reason, all crucible manufacturersprohibit the use of the tilting drive to force ofi skulls. It has beenfound in practice, however, that the skull is still forced olf by thetilting drive because this is the quickest, simplest and most convenientmethod.

It is an object of the invention to provide an apparatus which permitsof forcing off the skull by means of the tilting drive without risk ofadverse effects on the crucible drive.

The apparatus according to the invention promises a yielding forcing-01fnose associated with adjustable pressure limiting means which isarranged to be movable in an arcuate path described by the skull duringthe tilting of the crucible.

The forcing-off nose is desirably mounted on a hinged flap, which ishydraulically operated, and the hydraulic system comprises a pressurelimiting valve corresponding to the predetermined maximum of the forcetending to force olf the skull.

The forcing-oh surface of the forcing-01f nose should have such aninclination that a restoring component of force acting on theforcing-off nose and directed toward the pressure limiting means isobtained in the operative position while the skull is being forced olf.

The apparatus according to the invention has the advantage of permittingwith a very slight structural expenditure the use of the tilting drivefor forcing olf skulls, which practice is otherwise dangerous withregard to the guarantee.

The invention is illustrated in the accompanying drawing in anembodiment shown by way of example. FIG. 1 is a vertical sectional viewshowing a crucible with a skull at its mouth. FIG. 2 shows a preparatoryposition,

before the forcingcff. FIG. 3 shows the position for forcing-off theskull with the aid of the apparatus according to the invention.

In FIG. 1, 1 designates a typical form of a skull at the mouth of acrucible 2.

According to FIG. 2, an oxygen lance 3 mounted on the stand 4 is used tomake half-ring cuts 5 on opposite sides when the crucible is in atilted-down position e.g. at an angle of 18". In this way, a ring 6 iscut out at the narrowest part of the vessel to separate the outer cone 1from the inner cone 1".

In FIG. 3, the forcing-off nose 7 is carried by the hinged flap 8. Thelatter is hinged by a pin 9 to the main beam 10 of the platformstructure. The flap 8 is adjustable by means of the hydraulic cylinder11, which is suitably fed by a small rotary pump unit 12. In theposition shown in dotted lines, the flap is disposed outside the arcuatepath of the skull. In the position shown in solid lines, the flap is inoperative position on the arcuate path. The forcing-01f surface 13 ofthe forcing-01f nose is so inclined that the force tending to force offthe skull has always a component which acts on the flap and tends torestore the flap to its original position, when the friction between theskull and the forcing-0E nose is taken into account. The supportaiforded by the hydraulic cylinder opposes this component. In thisarrangement, the force tending to force off the skull can be limited bysetting a pressure limiting valve. When the force tending to force oifthe skull exceeds an allowable limit, which is determined by the drive,the valve will respond and the forcing-off flap will yield to theincreased force.

It is essential in the entire structure that the pump unit must bedesigned only for adjusting the forcing-off flap. This requires only asmall pressure and consequently a small power. The force tending toforce off the skull is applied through the crucible drive. To preventdamage to the crucible drive, the pressure limiting valve is mountedseparately from the pump installation.

What I claim is:

1. An apparatus for forcing off skulls from the mouths of tiltablesteelmaking converters, comprising a tiltable converter, a support, aflap hingedly connected to said support, a forcing-off nose on said flapmovable into a path described by a skull on said converter mouth duringthe tilting of said converter, a hydraulic pressure cylinder connectedto said flap and said support for forcing said nose against said skull,means for supplying hydraulic pressure to said cylinder and means forlimiting the pressure supplied to said cylinder to a predeten minedskull-severing pressure.

2. An apparatus as set forth in claim 1 wherein the forcing-01f surfaceof said nose is inclined at an angle such that the reaction forceproduced on said nose by a skull during forcing off of the skull isdirected to oppose the forcing action of said pressure cylinder.

References Cited UNITED STATES PATENTS 663,946. 12/1900 Waldburger etal. 2661 2,582,734 1/1952 Adams 24l239 X 3,197,187 7/1965 Lakin et al.266-36 FOREIGN PATENTS 358,565 3/1964 France.

I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

1. AN APPARATUS FOR FORCING OFF SKULLS FROM THE MOUTHS OF TILTABLESTEELMAKING CONVERTERS, COMPRISING A TILTABLE CONVERTER, A SUPPORT, AFLAP HINGEDLY CONNECTED TO SAID SUPPORT, A FORCING-OFF NOSE ON SAID FLAPMOVABLE INTO A PATH DESCRIBED BY A SKULL ON SAID CONVERTER MOUTH DURINGTHE TILTING OF SAID CONVERTER, A HYDRAULIC PRESSURE CYLINDER CONNECTEDTO SAID FLAP AND SAID SUPPORT FOR FORCING SAID NOSE AGAINST SAID SKULL,MEANS FOR SUPPLYING HYDRAULIC PRESSURE TO SAID CYLINDER AND MEANS FORLIMITING THE PRESSURE SUPPLED TO SAID CYLINDER TO A PREDETERMINEDSKULL-SEVERING PRESSURE.